1. Field
Example embodiments relate to methods of fabricating a photonic crystal, and more particularly, to methods of easily fabricating a photonic crystal having a desired photonic bandgap using an electrophoretic method.
2. Description of the Related Art
A photonic crystal is an artificial crystal that may be obtained by periodically arranging two or more substances having different refractive indexes in a two-dimensional or a three-dimensional lattice structure. A photonic crystal having a regular lattice structure may have a photonic bandgap that may disallow (prevent), or allow, light having a specific wavelength to pass through due to a periodic refractive index distribution. For example, in the case where an optical bandgap of a photonic crystal is formed in a band of visible spectrum and a frequency of light incident into the photonic crystal corresponds to the optical bandgap, incident light of not less than 99% can be reflected by the photonic crystal. On the contrary, most of incident light having a frequency other than the photonic bandgap goes through the photonic crystal. By using such a characteristic, a photonic crystal may be applied to a color filter of a display device. Also, to increase the light absorbance of a solar cell or increase the sensitivity of a light sensor using a phenomenon that light absorption increases drastically when the photonic band edge of a photonic bandgap coincides with a light-absorbing region of a light-absorbing substance, a photonic crystal may be applied.
The photonic bandgap of such a photonic crystal may vary according to refractive indices and periodic lattice structures of dielectric materials constituting the photonic crystal. Therefore, proper selection of types and lattice structures of dielectric materials enables to produce a photonic crystal having a desired photonic bandgap. Methods of producing a three-dimensional photonic crystal may include a top-down method using lithography, and a self-assembly method using a physical or chemical combination of colloidal particles and polymer. While the self-assembly method allows a three-dimensional photonic crystal to be produced at a relatively inexpensive cost, it requires a long process time and also has difficulties in realizing a desired photonic bandgap exactly. Thus, because many process steps are required to adjust the photonic bandgap exactly, process complexity is increased and production of a large-area photonic crystal is limited.